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I was in an aircraft yesterday waiting for its turn in the departure queue on the taxiway and noticed that the windsock was showing a direction approximately 30 degrees but directed along the direction we were entering the runway in. i.e. The parallel component would point in the take-off direction & not against it.

Made me wonder: Are there instances when lined up aircraft have to be made to taxi to the other end of a runway due to a last minute wind direction reversal?

Never happened to me, nor seen it mentioned in any ATC conversations / videos online so made me wonder.

Of course, if the parallel component is smaller than the allowable tailwind for the aircraft then I guess it does not matter?

curious_cat
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    Oh come on, this question specifically asks if there is ever a case where aircraft are asked to taxi along to the other end due to a wind change. The other questions are about traffic flow in the air and whether you can takeoff/land downwind. Can we please reopen this? – falstro Jun 10 '16 at 18:50
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    Yes, I have seem a case like that while spotting at a airport. The aircraft simply entered the runway at taxi speed and leave at the next exit, back to the taxiway going to the other runway threshold. It was not exactly lined up already, but holding short of runway when that happened. – ricardomenzer Jun 10 '16 at 19:05
  • This is actually answered in the top answer to this question here: http://aviation.stackexchange.com/questions/9126/how-does-a-large-airport-switch-flow?lq=1 – Jae Carr Jun 10 '16 at 19:41
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    @JayCarr no, it describes the procedure to switch the runway direction, not if the conditions ever changed so fast they needed to taxi waiting aircraft to the other end. – falstro Jun 10 '16 at 20:28
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    There are a few major airports with single runways, however I'm guessing that the chances of the wind doing a 180° flip in a short period of time is small, usually they'd be able to get the waiting aircraft out with a cross-wind while setting up new departures for a more favorable runway. – Ron Beyer Jun 10 '16 at 21:01
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    On a flight few years back we even commenced the take-off roll, aborted at low speed and taxied to the other end due to wind change. Apparently the pilots originally planned take-off with slight tail-wind and got report the wind increased beyond the tail-wind limit at the last moment (LIMJ is not that big, so there was no queue of departing aircraft). – Jan Hudec Jun 13 '16 at 16:33

2 Answers2

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What you are describing does happen. The runway change is a major event at a big airport and it usually occurs once a day. This becomes a major transition because landing aircraft have to be switched to the other end. AND, areas served by a single approach control, the change has to be coordinated with the other airports. Note that lines of aircraft waiting to take off rarely occur unless the airport is very busy and has few runways.

Thus, the runway change generally occurs over time (half an hour).

If there is a sudden, unpredicted wind change, generally, aircraft that are already at the "wrong" end of the runway are allowed to continue using it if they are able to do so.

So yes, aircraft will on occasion have to move to the other end of the runway.

I have seen this more frequently at busy general aviation airports than at commercial airport.

kevin
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user3344003
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    This occasionally happens at London Heathrow. The tailwind limit is 5kts and if the tailwind component is below that (from the East), aircraft will generally use the Westerly runways for noise reduction purposes. If the tailwind component rises above this and at 15:00 each day, operations are switched to the Easterlies. If the wind change is sudden and stronger than forecast, then a runway change can catch some poor souls at the wrong end of the runway who are then redirected to the other end. – Simon Jun 11 '16 at 00:08
  • I think I was at what you describe as a "very busy with few runways" airport. Mumbai, India. – curious_cat Jun 11 '16 at 02:24
  • It can happen at big airports too if the runways are parallel, which is common at airline hubs. For instance, KDFW has 5 parallels, so when they all reverse at the same time, it's a big deal. Such parallels tend to be very long to accommodate high crosswinds or even tailwinds so they can avoid/delay such reversals. – StephenS Nov 08 '18 at 04:40
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This goes back a few years, but I was on a 727 departing LGA, and we had to abandon our position in the queue to taxi to the other end. Everyone was all ready taking off with a tailwind but the aircraft weight and airline opspec would not permit us to launch. We had to taxi to the other end but soon all the other planes joined us, because the wind was increasing over time. Net result we took off sooner! Happy dance!

Skip Miller
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